Epidemiological evidence indicates an association between obesity and acute lung injury (ALI), but the molecular mechanisms mediating this association are poorly understood. Adiponectin is an adipose tissue-derived hormone that is present in high concentration in serum of humans and rodents and has well-documented anti-inflammatory and vascular protective properties in murine lung. Moreover, we recently demonstrated adiponectin to protect against development of LPS-induced ALI in mice and showed higher circulating levels are linked to increased mortality in patients with established acute respiratory failure of diverse etiologies. Together, these data support the notion that adiponectin plays an important role in lung homeostasis and disease. In this program, we will leverage existing clinical data and bio-specimens collected as part of the NIH ARDSNet Fluid and Catheter Treatment Trial in order to spearhead investigation into role of adiponectin in acute lung injury. This project will investigate the hypotheses that: 1) higher circulating levels f adiponectin in patients with ALI are linked to a more severe lung injury phenotype; and 2) higher plasma levels of adiponectin are associated with increased mortality. Overall, we believe these studies will establish adiponectin as a novel prognostic marker in ALI and will provide the foundation for future more mechanistic studies into the role of adiponectin in ALI.